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            <h2 class="title" style="clear: both"><a id="dbset_append_recno"></a>Db::set_append_recno()</h2>
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      <pre class="programlisting">#include &lt;db_cxx.h&gt;
 
int
Db::set_append_recno(int (*db_append_recno_fcn)(DB *dbp, Dbt *data, 
                                                db_recno_t recno));</pre>
      <p>
         When using the <a class="link" href="dbput.html#dbput_DB_APPEND">DB_APPEND</a>  
         option of the <a class="xref" href="dbput.html" title="Db::put()">Db::put()</a>  method, it may be
         useful to modify the stored data based on the generated key. If a
         callback function is specified using the 
         <code class="methodname">Db::set_append_recno()</code>         
         method, it will be called after the record number has been selected,
         but before the data has been stored.
    </p>
      <p>
         The <code class="methodname">Db::set_append_recno()</code> method configures operations performed
         using the specified <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a> 
         handle, not all operations performed on the underlying database.
    </p>
      <p>
             The <code class="methodname">Db::set_append_recno()</code> method may not be called after the 
             <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a>  method is called.
    </p>
      <p>
         The <code class="methodname">Db::set_append_recno()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
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      <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
        <h3 class="title">Note</h3>
        <p>
                    Berkeley DB is not re-entrant. Callback functions should not attempt to make
                    library calls (for example, to release locks or close open handles). Re-entering
                    Berkeley DB is not guaranteed to work correctly, and the results are undefined.
            </p>
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              <h3 class="title"><a id="idp4868328"></a>Parameters</h3>
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                <h4 class="title"><a id="idp4599528"></a>db_append_recno_fcn</h4>
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          <p>
                          The <span class="bold"><strong>db_append_recno_fcn</strong></span> parameter is
                          a function to call after the record number has been selected but
                          before the data has been stored into the database.  The function takes
                          three parameters:
                     </p>
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                <p>
                        <code class="literal">dbp</code>
                    </p>
                <p>
                         The <span class="bold"><strong>dbp</strong></span> parameter is the enclosing
                         database handle.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">data</code>
                    </p>
                <p>
                             The <span class="bold"><strong>data</strong></span> parameter is the data 
                             <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>  to be stored.
                    </p>
              </li>
              <li>
                <p>
                        <code class="literal">recno</code>
                    </p>
                <p>
                         The <span class="bold"><strong>recno</strong></span> parameter is the generated
                         record number.
                    </p>
              </li>
            </ul>
          </div>
          <p>
                    The called function may modify the data 
                    <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>. If the function needs to allocate
                    memory for the <span class="bold"><strong>data</strong></span> field, the 
                    <span class="bold"><strong>flags</strong></span>  field of 
                    the returned <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>
                    should be set to <code class="literal">DB_DBT_APPMALLOC</code>, which indicates that 
                    Berkeley DB should free the memory when it is done with it.
            </p>
          <p>
                    The callback function must return 0 on success and 
                    <span class="bold"><strong>errno</strong></span> or a value outside of
                    the Berkeley DB error name space on failure.
            </p>
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      <div class="sect2" lang="en" xml:lang="en">
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              <h3 class="title"><a id="idp4785640"></a>Errors</h3>
            </div>
          </div>
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        <p>
                         The <code class="methodname">Db::set_append_recno()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
                    </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp3919096"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
                If the method was called after <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> 
                was called; or if an invalid flag value or parameter was specified.
            </p>
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              <h3 class="title"><a id="idp3851616"></a>Class</h3>
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        <p>
                <a class="link" href="db.html" title="Chapter 2.  The Db Handle">Db</a>  
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              <h3 class="title"><a id="idp4073016"></a>See Also</h3>
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        <p>
                     <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> 
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